NAOMI ARNOLD: Meditation is usually thought of as a seated, sedentary activity that can relieve stress, but you discovered that it can also increase physical activity in people’s daily lives.

JACOB MEYER: Yes. This study comes from a large randomized controlled trial evaluating the effectiveness of mindfulness-based stress reduction training, or MBSR training. The program we used was designed around reducing stress. It was developed at the University of Massachusetts by Jon Kabat-Zinn, and was the first widely-used mindfulness program in the United States.

It had a variety of outcomes, but one involved participants split between; getting MBSR for eight weeks; participating in a matched aerobic exercise training group for eight weeks; or in a control group. We had people wear accelerometers for a week before being randomized into the groups, then ran the interventions, and then they wore the accelerometers for a week afterward to see if their physical activity changed. We wanted to find whether people were being more active, less active or about the same before and after.

What did you discover in the study?

This was done in fall to winter, and we saw that the control group decreased their physical activity by a pretty large amount whereas both the exercise and the meditation group maintained or slightly increased their activity over those two months.

Did these results surprise you?

Totally. These were not what I expected. I thought that the meditation group might provide some benefit compared to the control group, but I didn’t expect it to provide the benefit that it did – comparable to the aerobic exercise.

I also thought that we were going to see participants in the meditation group end up being more sedentary or having more time seated during the day, and that wasn’t the case. Instead we saw no shift towards being more sedentary, and much more activity than I had expected.

How might this help promote physical activity?

We’re really just trying to figure out why this happened, when we didn’t think it was going to. The usual way of thinking about exercise is we have someone come in and work out with a trainer in the gym, and that’s going to lead them to being more active afterwards and to all these health benefits. These results made us take a step back and think: can we get someone to become a little bit more mindful, a little bit more present and aware in what they are doing? Might that increased mindfulness end up leading that person to make choices that include more physical activity in their life? And might that be as effective in increasing someone’s physical activity as what we normally have them do, which is come into a gym?

I’m just still amazed by the fact that the meditation group had similar effects on physical activity as the aerobic exercise training group. As a kinesiologist, considering what we think about and the way we prescribe exercise, this is totally not what I would have expected.

What were some of the participants’ thoughts about their behavior?

We had people record what they thought their physical activity was over the last week both before and after the intervention. The meditation group reported similar levels of physical activity before and after the intervention, and largely that’s what happened when we actually had them wear the accelerometers. But the exercise group said they did substantially more activity. When we looked at the accelerometers they did only a little bit more.

What I took from that was that the meditation group was more accurate in their representation of how they were active.

So the ones trained in mindfulness were more aware of their bodies and their activity?

They were able to say “I don’t think I’ve changed my activity”, and that was the case. Whereas the exercise group didn’t change their activity but they said that they increased it substantially. The control group said they didn’t think they changed their activity and they actually decreased by a good amount. The meditation group was the only group that matched in terms of what they thought they did and what we saw from the physical activity monitors.

However, there were only 49 people split across the three groups. There were 14-18 per group in the end and we would really need to see this replicated in a larger trial to know if these are true effects of these interventions.

MINDFULNESS & MUSCLE IN A NUTSHELL:

Although meditation is usually associated with sedentary behavior, spending more time meditating doesn’t result in more sedentary behavior overall.

Increased mindfulness can lead you to make choices that lead to more physical activity.

Mindfulness meditation can also foster a more accurate perception of your level of physical activity.

A mindfulness training program might help you make behavioral changes, like boosting physical activity.

We have long known that cardio exercise is good for the mind, now a recent study indicates resistance training can reduce symptoms of depression.

The specifics of the training aren’t important, it may just be the idea of building strength that aids mental health.

So it is clear that mindfulness has an effect on physical activity, but what about the effects of physical activity on the mind? You’ve been involved in an analysis of clinical trials on strength training to see whether that has the same effect as running and aerobic training. Can you tell us about that?

There has been a lot of information about how aerobic exercise such as running influences the body, but there has been a whole lot less that looks at resistance exercise training. This study tried to figure out: is resistance training giving us the same effect as we see from aerobic exercise training? Or is it giving us something different? What we saw is it’s about the same in terms of general effects.

The strength training was associated with a moderate reduction in symptoms of depression, which is about the same effect as we would see from aerobic exercise training, from antidepressant medications, or from psychotherapy.

Can we pinpoint what about exercise is actually improving mood? Is it physiological? Is it the feeling of accomplishment?

­I wish we could say with certainty. The biological mechanisms underlying aerobic exercise aren’t well understood, and we know even less about how resistance exercise training influences mental health from a practical biological standpoint. Part of that problem is that it isn’t perfectly clear where mood resides in the brain or in the body. There is no one specific abnormality that we know about that causes depression – it’s a very complicated disease. There are many different ways that people can get there, and there are a bunch of different ways that people can present clinically when they are depressed. So that makes it a lot harder to say, “This is how exercise treats this condition”.

There are a number of exciting potential theories. Is it self-efficacy: do people feel more confident in performing tasks? It is the socialization that often happens when people exercise? Or is there some biological explanation that maybe relates to those, but is driven by changing levels of neurotransmitters or some other agent within the brain?

Something I thought was interesting in the strength training study, and not necessarily what I expected, was that whether or not people’s strength improved over the course of their resistance training program didn’t matter in terms of whether or not they were going to have lower symptoms of depression. You would think – in particular if it’s a specific muscle-building physiological change that drove the anti-depressive effects – that increased strength would have to happen for someone’s depressive symptoms to go down. But that didn’t seem to be the case.

So it could be just the action of getting off the couch and working out?

Potentially! Or it could be that the effect occurs before the person gets to the gym. Getting out of their routine, going down to the gym, getting everything ready and starting it – and the benefits have already happened. What they do when they get there, and whether or not they get stronger might not be the most important piece, although that’s just speculation.

Given all your research, how can people use exercise to improve their mental and physical health?

The resistance exercise training study would suggest that people who maybe haven’t identified themselves as a runner shouldn’t necessarily throw all exercise out the window, but might be able to consider different types of exercise, such as resistance exercise training, and still see really useful benefits on psychological health.

For physical health, I think the mindfulness study is really interesting in that mindfulness training might be something that one could consider if they are thinking about changing their physical activity. Or maybe in the past they thought about changing how active they are but haven’t been able to stick with it. Maybe going through a mindfulness training program might help them to make that behavioral change that was elusive in the past.

What’s next for that area of research?

I think our findings need to be confirmed in future, larger studies. But also, we really need to start thinking about re-evaluating the ways we help people change behavior. Having someone come into the gym and work out with a personal trainer is great for the percentage of people it works for, but for the large percentage of people that it doesn’t work for, how can we help them become more active? The early signs are exciting: mindfulness might be one of those methods.

What’s next for you?

My personal research track is really trying to figure out how we can incorporate exercise into the treatment of depression. Probably not as a standalone treatment, but as part of a multi-component treatment that includes other types of therapy, either medication or psychotherapy, and includes exercise as an intentional, structured component of that.

I really think the benefits you see from exercise have the potential to be independent of benefits seen from other types of therapy, so including it could be really useful.

I’m also interested in trying to figure out what some of those mechanisms underlying the antidepressant effects of exercise might be. How is exercising changing mood? What is it that’s happening biologically? There have been some great animal studies, but if we really start to uncover how that happens in humans we can figure out what’s going on in the body that helps people feel better after exercise. Then we can target that specifically, and have much more effective programs than we have available right now.

MINDFULNESS VS MEDITATION

While these two terms are often used interchangeably, generally mindfulness is about becoming more aware of the present moment during any waking situation. Meditation often has elements of mindfulness, but it is more formal as it involves dedicating a specific time to foster inner peace.

Assistant Professor Jacob Meyer is a kinesiologist at Iowa State University researching exercise psychology: how exercise, physical activity, and movement influences the way people think and feel. He has a particular focus on exercise for the treatment of mental health conditions.